On Fri, 8 Jul 2022 at 15:14, Hans de Goede <hdegoede@xxxxxxxxxx> wrote:
>
> Commit 98f30d0ecf79 ("ACPI: power: Switch to sys-off handler API")
> switched the ACPI sleep code from directly setting the old global
> pm_power_off handler to using the new register_sys_off_handler()
> mechanism with a priority of SYS_OFF_PRIO_FIRMWARE.
>
> This is a problem when the old global pm_power_off handler would later
> be overwritten, such as done by the late_initcall(efi_shutdown_init):
>
> if (efi_poweroff_required())
> pm_power_off = efi_power_off;
>
> The old global pm_power_off handler gets run with a priority of
> SYS_OFF_PRIO_DEFAULT which is lower then SYS_OFF_PRIO_FIRMWARE, causing
> acpi_power_off() to run first, changing the behavior from before
> the ACPI sleep code switched to the new register_sys_off_handler().
>
> Switch the registering of efi_power_off over to register_sys_off_handler()
> with a priority of SYS_OFF_PRIO_FIRMWARE + 1 so that it will run before
> acpi_power_off() as before.
>
> Note since the new sys-off-handler code will try all handlers in
> priority order, there is no more need for the EFI code to store and
> call the original pm_power_off handler.
>
> Fixes: 98f30d0ecf79 ("ACPI: power: Switch to sys-off handler API")
> Cc: Dmitry Osipenko <dmitry.osipenko@xxxxxxxxxxxxx>
> Signed-off-by: Hans de Goede <hdegoede@xxxxxxxxxx>
Acked-by: Ard Biesheuvel <ardb@xxxxxxxxxx>
Note that, as far as I know, this should only affect x86 even though
this is generic EFI code, and arm64 also supports ACPI boot, but it
doesn't use ACPI for poweroff/reboot etc
> ---
> drivers/firmware/efi/reboot.c | 21 +++++++++++----------
> 1 file changed, 11 insertions(+), 10 deletions(-)
>
> diff --git a/drivers/firmware/efi/reboot.c b/drivers/firmware/efi/reboot.c
> index 73089a24f04b..ceae84c19d22 100644
> --- a/drivers/firmware/efi/reboot.c
> +++ b/drivers/firmware/efi/reboot.c
> @@ -6,7 +6,7 @@
> #include <linux/efi.h>
> #include <linux/reboot.h>
>
> -static void (*orig_pm_power_off)(void);
> +static struct sys_off_handler *efi_sys_off_handler;
>
> int efi_reboot_quirk_mode = -1;
>
> @@ -51,15 +51,11 @@ bool __weak efi_poweroff_required(void)
> return false;
> }
>
> -static void efi_power_off(void)
> +static int efi_power_off(struct sys_off_data *data)
> {
> efi.reset_system(EFI_RESET_SHUTDOWN, EFI_SUCCESS, 0, NULL);
> - /*
> - * The above call should not return, if it does fall back to
> - * the original power off method (typically ACPI poweroff).
> - */
> - if (orig_pm_power_off)
> - orig_pm_power_off();
> +
> + return NOTIFY_DONE;
> }
>
> static int __init efi_shutdown_init(void)
> @@ -68,8 +64,13 @@ static int __init efi_shutdown_init(void)
> return -ENODEV;
>
> if (efi_poweroff_required()) {
> - orig_pm_power_off = pm_power_off;
> - pm_power_off = efi_power_off;
> + /* SYS_OFF_PRIO_FIRMWARE + 1 so that it runs before acpi_power_off */
> + efi_sys_off_handler =
> + register_sys_off_handler(SYS_OFF_MODE_POWER_OFF,
> + SYS_OFF_PRIO_FIRMWARE + 1,
> + efi_power_off, NULL);
> + if (IS_ERR(efi_sys_off_handler))
> + return PTR_ERR(efi_sys_off_handler);
> }
>
> return 0;
> --
> 2.36.0
>
